I'm trying to adapt a FoxPro 2.6a program to a VFP5a form and I can't get a handle
on the ON ERROR command. I'm using Graphics Server, a 3rd-party graphing library,
to create polygons of every state in the U.S. In FPW 2.6, I have an ON ERROR DO NOTHING
error routine that goes to the procedure, NOTHING, and returns without doing anything.

I have to do this in case there is a call to a nonexistant state polygon procedure. The
program would bomb out otherwise. I can't seem to get this to work in a VFP5 form.

How do I go about doing this? The state polygon procedures I mentioned above are now
methods in the form. Listed below is the CLICK method - everything works except the ON
ERROR call.

*:===============================================
*: Object: cmdMap
*: E/M: CLICK
*: Purpose: Draws state polygons when user
*: clicks the Redraw Map command
*: button.
*:===============================================
r=GSUseView(THISFORM.oleMap.NWin,0) && Make sure we are using the correct GS View.
THISFORM.oleMap.Background = 7 && Assign gray to background color.
THISFORM.oleMap.GraphType = 0 && Do not display the default graph.
THISFORM.oleMap.DRAWMODE = 1 && Clear the view.
THISFORM.SplitSet() && Call method assigning default coordiates.

ON ERROR DO THISFORM.Nothing && Call dummy error handler method so we won't
*: bomb out when calling nonexistent methods.

SELECT states && Go to the STATES table workarea.

SCAN && Scan the entire STATES table.
IF BETWEEN(terr,"5","6") AND SUBSTR(stcode,3,1)="0" && For testing, limit call to state borders in the
*: WEST and SOUTH territories.
cMapPoly = "THISFORM.ST"+states.stcode+"()" && Create a string for the method call.
&cMapPoly && Call the method containing the state polygon array.
DIMENSION aNewState[ALEN(THISFORM.aMap,1),2] && Redimension the array used by Graphics Server.
=ACOPY(THISFORM.aMap,aNewState) && Copy the state polygon array data to the GS array.
=GSFixPos(THISFORM.aFixPos[1,1],THISFORM.aFixPos[2,1]) && Fix the XY positions in the GS view.
=GSDataDim(ALEN(aNewState,1),2) && Establish the data dimensions for GS.
=GSDataAmp(ALEN(aNewState,1),2,@aNewState[1,1]) && Send the data to GS.
=GSPolyFill(0,0,0,0,0,6) && Draw a polygon with the array's dimensions.
=GSPolyVec(0,0,0,0,0,0) && Draw a line around the polygon.
DO CASE
CASE stcode = "580" && If the state is US Virgin Islands,
FOR lnSupp = 1 TO 2 && draw supplemental polygons (numerous islands).
cSupp = ALLTRIM(STR(lnSupp,1,0))
cMapPolyPlus = SUBSTR(cMapPoly,1,LEN(cMapPoly)-2)+cSupp+"()"
&cMapPolyPlus
DIMENSION aNewState[ALEN(THISFORM.aMap,1),2]
=ACOPY(THISFORM.aMap,aNewState)
=GSFixPos(THISFORM.aFixPos[1,1],THISFORM.aFixPos[2,1])
=GSDataDim(ALEN(aNewState,1),2)
=GSDataAmp(ALEN(aNewState,1),2,@aNewState[1,1])
=GSPolyFill(0,0,0,0,0,6)
=GSPolyVec(0,0,0,0,0,0)
ENDFOR
CASE stcode = "110" && If the state is Hawaii,
FOR lnSupp = 1 TO 7 && draw supplemental polygons (numerous islands).
cSupp = ALLTRIM(STR(lnSupp,1,0))
cMapPolyPlus = SUBSTR(cMapPoly,1,LEN(cMapPoly)-2)+cSupp+"()"
&cMapPolyPlus
DIMENSION aNewState[ALEN(THISFORM.aMap,1),2]
=ACOPY(THISFORM.aMap,aNewState)
=GSFixPos(THISFORM.aFixPos[1,1],THISFORM.aFixPos[2,1])
=GSDataDim(ALEN(aNewState,1),2)
=GSDataAmp(ALEN(aNewState,1),2,@aNewState[1,1])
=GSPolyFill(0,0,0,0,0,6)
=GSPolyVec(0,0,0,0,0,0)
ENDFOR
ENDCASE
ENDIF
ENDSCAN
THISFORM.BorderAbbv() && Call the method placing state abbreviations on polygons.
ON ERROR && Close the ON ERROR routine.